Not sure if I'm the last to know about this but it's news to me. Since my company switched to a new unaffordable insurance plan that does not cover HRT all options are on the table. Why not try and upgrade if we can? Judging by the phrase "one option for extreme cases" it would appear Blue Cross has preempted the generally accepted diagnosis and will put the onus on the patient to prove their gender dysphoria is 'extreme' enough to warrant SRS. (jumping through cisnormative binary hoops)
Reading the Clinical UM Guideline it becomes apparent the devil is in the details so read it carefully and be fully aware of your options. But most importantly, since you are dealing with a commercial enterprise intent on giving you the least for your money, be beware.